Evaluation of different surgical methods in treating recurrent patella dislocation after three-dimensional reconstruction

Purpose Recurrent patella dislocation (RPD) is the most common complication of patellar instability. The effects of different surgical techniques on the outcome of RPD treatments remain unclear. This study was conducted to compare the effects of three surgical techniques in treating RPD by three-dimensional (3D) reconstruction from computed tomography (CT) scans. Methods Sixty-eight patients with RPD and no previous surgical treatments who attended our hospital between October 2010 and 2013 were enrolled and randomly assigned into three groups: (1) medial patellofemoral ligament (MPFL) reconstruction and medial patellar retinaculum (MPR) plication group; (2) lateral patellar retinaculum (LPR) release and MPR plication group; and (3) MPFL reconstruction and LPR release group. Knee joints with flexion of 20A degrees were scanned by a 64-row CT scanner and 3D reconstructed. Congruence angle (CA), patellar tilt angle (PTA), lateral patellofemoral angle (LPFA), and congruence of the lateral patellofemoral articular surface were measured. Knee joint function was evaluated by the Lysholm knee scoring scale, Kujala patellofemoral score, and International Knee Documentation Committee (IKDC) score. Results Pre-operative clinical characteristics were similar across groups. After treatment, the CA, PTA, and LPFA were reverted to normal post-operatively without statistically significant between-group differences. The MPFL reconstruction and LPR release group had the highest congruence of the lateral patellofemoral articular surface; while the (LPR) release and (MPR) plication group had the lowest Lysholm knee scoring scale, Kujala patellofemoral score, and IKDC score after surgery. Conclusions The MPFL reconstruction and LPR release group had the best clinical outcomes among the three surgical methods, as indicated by better joint congruence after 3D joint reconstruction and higher knee function scores.